The first red flag here is smoking pot! I was a huge pot head before all this began to occur, and if its not directly relative to anxiety it definitely plays a roll...and its funny you describe that because my anxiety is brought on in the identical platform, anytime I feel indifferent, or like I relax and finally can't hear my heart beating or feel it beating I freak like it has stopped, essentially because what was normal has escaped me and I attribute normalcy as danger in some sick sense. And upon deeper review I believe that weed played a roll in that, since weed takes so long to leave your system (up to 8 weeks in some cases) every time that you smoke the chemicals weed manifests in you continue to constantly build up in your fat and body, and if you keep smoking you never give your body a chance to get rid of those toxins and look at the both of us now : /. It is very interesting, as all this began to occur I stopped smoking pot, about 8 weeks or so now, but tried it 1.5 times since and each time I bugged hard. And tried to stay calm but my anxiety took over, perhaps because it intensifies feelings your already having, but what I will say is my first 2 panic attacks occurred after or during being high...soo perhaps from there it was all cognitive learned behavior in some way or another, because things just kept getting worse and worse because I went from saying oh I just bugged out high too Im dying or have something wrong with me somehow...do me a favor stop smoking!! and get your head straight, Im completely sober I don't drink smoke or anything and its because I miss being normal so so much, that the idea of having set backs or being abnormal in anyway turn me off so much, personally I can't wait until I am just myself again. Good luck too you!
If if helps, I have the same super sensitivity to my body sensations. I understand that it is just one of the ways that anxiety can manifest in people. After suffering my first panic attack, which was dizziness, shortness of breath, tingling in arms and legs, head fogginess or floating sensation, etc, I now start to freak out anytime my body feels any one of these things. If I stand up to fast and get a little dizzy, I begin to think about panic..If my arm falls asleep my automatic reaction is that its all starting, or something like that. I dont know why this happens, but I know it is really hard to change your course of thought. Thats what I do..I try as hard as I can to tell myself its nothing...to lie down if I feel dizzy until it passes, to shake my arms and legs out until the tingling stops..tell myself this is normal, this is from my arm falling asleep or whatever it is.
As far as smoking pot, I dont know about how that affects anxiety, but I would imagine that any drug use would aggravate it. I wouldnt want to do anything mind altering and make my anxiety worse. I do know that they tell you not to drink alcohol or smoke becuase they can make anxiety worse. Myself, I cant even drink caffeine without it making me shaky and starts the anxious feelings.